Recently, there are known several methods of green tyre production and the corresponding devices and assembling apparatus. Each of them shows some merits or advantages in comparison with the other, but also some shortcomings. Actually, the structural solution of particular devices, their arrangement and mutual interconnection determines the corresponding method of green tyre production.
Most of the tyre building lines are designed in the so-called single-line arrangement, where the intermediate products necessary for the green tyre production are supplied, pretreated and completed to the final product on tyre building drums, which are usually arranged on one longitudinal axis of the line. In a line with such an arrangement, it is very difficult to utilize new progressive elements concerning both the structural solution of its particular devices and introducing more progressive methods of green tyre production and optimization of the technological process of the production.
Also known are apparatus for green tyre production, the particular stations of which are arranged on several axes. The U.S. Pat. No. 5,853,525 discloses an apparatus for radial tyre production by a method in which the tyre carcass is formed to a cylindrical shape in advance and expanded on a shaping drum so as to wrap the bead core bundles with apices. Subsequently an inner liner is slipped into the carcass in a first transfer ring, the ply having a smaller diameter than that of the carcass cylinder and being pressed against its inner surface, thus creating a first assembly. During this time on a second band forming drum, sidewalls and reinforcing bands are formed into a cylindrical shape to wrap the bead cores so as to provide a second assembly of sidewalls having a smaller diameter than that of the first assembly. At that time the first transfer ring holding the first assembly and the second band drum are moved coaxially relative to each other. After the second assembly is arranged in a predetermined position within the first assembly, the second assembly is expanded and pressed against the first assembly, thus creating a third assembly. The first transfer ring and the shaping drum move to a determined position and the third assembly, disposed in the first transfer ring, is transferred onto the shaping drum. Then the shaping drum is expanded and the bead core holders move against each other to create a round form of the shaped green tyre. A belt-tread assembly which has been previously formed into a cylindrical shape on a further band drum, is supplied by means of a second transfer ring and attached to the third assembly during shaping. Herewith the green tyre production is completed. Servisers with the corresponding materials are assigned to all of the above drums.
This method can be accomplished on an apparatus which is arranged on two parallel axes, the first and the second band drum as well as a device for supplying the bead cores and plies being arranged on one axis, and the shaping drum and a drum for making the belt-tread assembly in advance being arranged on the second axis.
This method can be accomplished also on an apparatus, which is arranged on three parallel axes, where the second band drum is arranged on the middle axis.
EP 597125 B1 discloses an apparatus for tyre production comprising a band drum, a shaping (building) drum and a device comprising two belt forming drums which can be oscillated or cyclically moved, where the band drum and the device with two belt forming drums are disposed on one axis in opposing relationship. The shaping drum is disposed so that it can be reciprocated between a position on the aforesaid axis, and a stand-by position maintaining the parallel condition with respect to the above axis. The carcass and belt transfer units are disposed so that they can be reciprocated along the aforesaid axis between the band drum and the belt forming device.
EP 880436 B1 describes an apparatus for production of green tyres for vehicles, consisting of a first machine house with two coaxially disposed belt building shafts extending in a first horizontal main direction, where the first shaft is carrying a belt building drum and the second shaft is carrying a tread building drum, this drum being disposed at a greater distance from the first machine house along the first horizontal main direction. Drives for these shafts are independent. The apparatus further comprises a second machine house with a shaft rotating along a second horizontal main direction, which is parallel to the first horizontal main direction. The shaft of the second machine house is carrying two carcass shafts, which are arranged parallel to each other at a certain distance, where the first shaft is carrying a first carcass drum and the second shaft is carrying a second carcass drum. The shafts are driven independently and they are rotationally arranged in such a way that each of them can be brought onto the axis of the first horizontal main direction. The apparatus comprises a transfer track with transfer direction parallel to the first horizontal main direction, on which there are disposed a first transfer ring movable between the belt building drum and the tread building drum, and a second transfer ring movable between the tread building drum and a carcass drum, rotated in line with the axis of the first main direction. On the transfer track, there is disposed a unit for holding and placing the bead cores on the carcass drum, which is rotated in line with the axis of the first main direction. The apparatus further comprises servisers for particular components, a stitching device, disposed below the shaping drum, and a unit for removing the complete tyres.